1. Field of the Invention
The present invention generally relates to devices for preparing the terminal end of a telecommunications line (whether voice, data, video, etc.) so as to improve the quality of a connection in the line, and more particularly to a device for cleaning the end face of an optical fiber to be interconnected with another optical fiber or with an optoelectronic component.
2. Description of the Prior Art
Optical fibers have replaced copper wire as the preferred medium for carrying telecommunications signals. As with copper wire, it is necessary to provide for the interconnection of optical fibers, during installation, repair or replacement of the fibers, and to terminate the fibers onto active optical devices. There are generally two kinds of interconnection devices, splices and connectors. The term "splice" usually refers to a device which provides a permanent connection between a pair of optical fibers. The term "connector," in contrast, usually refers to a device which may be engaged and disengaged repeatedly, often with a different plug or receptacle. A connector may also refer to the plug portion of a fiber termination, which is attached to an optical device. Optical devices include, for example, optical sensors (photoelectric diodes) and light sources (LED's, laser diodes). The termination of an optical fiber may be indirect, i.e., the fiber may be connected to some other (passive) optical device such as a beam splitter or polarizer, before the light beam is directed to the active optical device. The present invention is generally directed to cleaning the terminal end face of an optical fiber to be used in a connector or splice, but these terms should not be construed in a limiting sense since the present invention may be used in plug and receptacle designs which provide a permanent or temporary connection or termination.
In the fiber optic connector described in U.S. Pat. No. 5,381,498, the connector has a plug and a receptacle, the plug having a fiber-receiving, V-shaped groove for each fiber to be interconnected, with the end of the fiber terminating in the middle of the groove. The receptacle has a plate which retracts as the plug is inserted, whereby another fiber is lowered into the V-groove of the plug. Upon full insertion of the plug, the two fibers ends are in contact, and the fiber secured to the receptacle is elastically deformed to maintain a continuous compressive load between the terminal ends of the fibers. The connector provides for the quick disconnection and reconnection of a plurality of optical fiber pairs, without the use of ferrules or other alignment members. High strength fiber may be used to withstand repeated insertions and bowing of the fibers. The exact lengths of fibers (i.e., the relative locations of their terminal ends in the plug and receptacle) are not critical since tolerance is provided by the slack taken up in the bowed receptacle fiber (the terminal portion of the fiber secured to the plug does not bow, but always remains straight). The ends of the fibers may be prepared by simply cleaving and beveling; the end faces may optionally be cleaved at an angle (i.e., non-orthogonal to the fiber axis) to reduce signal reflections.
In the connector of the '498 patent, it is incumbent upon the user or craftsperson installing the plug or receptacle to keep the terminal end faces of the fibers as clean as possible, to minimize losses in light transmission across the connection. Since this design is intended for repeated insertion of a plug into a receptacle, it is possible that the plug fiber ends will become contaminated while the plug is outside of the receptacle, and it is also possible for dust to enter the receptacle and contaminate the fibers therein. It therefore may become necessary to clean the fibers after they have been affixed to the plug or receptacle housing. When originally installing the fibers, they are commonly cleaved to yield a fractured end face which may be further polished or beveled, and then cleaned by wiping the end with a lint-free cloth which has been dipped in, e.g., isopropyl alcohol. This task is difficult to accomplish after installation, since in many designs, such as the '498 receptacle, the fibers are located within a housing in such a manner that they are difficult to access.
Another fiber cable cleaner, sold by Molex, is essentially a box with a window, and a spool of lint-free cloth located in the box. By opening a door at the window, a portion of the cloth is exposed such that the fibers may be pushed against the cloth surface for cleaning. This design also requires that the fibers be freely exposed.
Japanese Patent Application (Kokai) no. 7-287124 describes the use of a cleaning media to clean an optical fiber. A solvent is directed at the cleaning strips while a fiber end is held between the strips. This device, however, also requires the fiber to be exposed so that it can be inserted into the device, and further cleans the sides of the fiber but does not necessarily clean the fiber tip. It would, therefore, be desirable and advantageous to devise a fiber optic cable cleaner which not only allows cleaning of fiber end faces which are otherwise inaccessible within a connector housing, but which further avoids the use of liquid solvents that must be applied to the fibers or cleaning media.